1.188.1. RHSA-2011:0496: Important xen security update
Updated xen packages that fix several security issues are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.
The xen packages contain administration tools and the xend service for managing the kernel-xen kernel for virtualization on Red Hat Enterprise Linux.
It was found that the xc_try_bzip2_decode() and xc_try_lzma_decode() decode routines did not correctly check for a possible buffer size overflow in the decoding loop. As well, several integer overflow flaws and missing error/range checking were found that could lead to an infinite loop. A privileged guest user could use these flaws to crash the guest or, possibly, execute arbitrary code in the privileged management domain (Dom0). (CVE-2011-1583)
All xen users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.